Electric induction furnace



(l FQHSK ELECTRC INDUCTION FURNACE Filed Jan. 16, 1922 W s W ,M

Patented Feb. 12, 1924.

UNITED STATES OTTO FRICK, OF HERSERUD, SWEDEN.

ELECTRIC TNDUGTTON FUBNACE.

Application tiled January 16, 1922-. Serial No. 529,734.

To ail who/m, anni; concern.'

Be it known that I, (h'ro FinCK, a citizen oi the Kingdom of Sweden. residing .at llersernil7 fiivcden. have invented new and uaclnl improvements in Electric `Induction lian-nacen. ol which the 'followingl is a spec-'r lication.

Thia1 invention relates; to electric induction furnaces vlor melting; and refining steel and other metals.

lt is woll-'known that the. greatest hin- 'ilrance in continuously Working Such turnaces consists. in the corroaion ofthe walls oi the meltingr channel, which takes place especially at the inner wall oi the channel and malien it necessary 'from time'to time to interrupt the operation for repair, The said corrosion seems lo an essential (lcfrrle lo depend on the rotation of the melting bath nhich caused hy the magnetic tlux out side the ironcore and takes place in every cross-section of the hath in such direction that the uppermost layer of the molten mass is continuouely tlowing against the inner vvall ot the channel. `With the form of the cross-Section of the melting channel usually used in induction furnaces in vwhich the side `-:alla oi' the channel are vertical or nearly vertical it impossible to repair the walls oi' the channel during the Working,v as the rei'iairingg mate-rial cannot he made to adhere on the walls ot' the channel.

The object oi the present invention is to remove .said huur-haelt hy an improved form of the croise-section ot the melting channel.

The invention consists, chiefly. in giving to the inner `wail or the inner as well as the outer ivall oi the melting (flannel 4such small inclination that it will he possible to apply. Y

and sintcr on repairing material for repairing corroileifl parte of the melting channel when the furnace is tapped or hy incliningj the furnace during the oi'ieration so much lihatthc corroded parte ol the channel walls` are uncovered.

lin the acciinipanyingy showin diaggrannnatically two einhodimcntis oi my ii'irenlion. Figi. l shows a Vertical cross-section ot one embodiment ol the inventionand Fig. 2- shows a similar View ot another embodiment.

Referring to the drawing, i is the 'iron core of the Jurnaee, 2 the ijn'iinary coil, il the rinwshapcd hearth and 4 a cover on the hearth." iiccoriling to Fin'. l lioth side wills 5, 3 of the melting channel have such arnali drawing` l have inclinationv that the cross-section of the channel has the Shape of an open V. It wilt on account thereotl be possible to repair the channel during the Working of ,the furnace and especially when tapping the furnace by applying repairing material such as niagnesite and the like on the parts ofthe channel walls which have been damaged by the molten hath. 0n account of the high temperature in the furnace said lmziterial is rapidly sintered and caused to adhere on the Walls. Preferably the cover is for that' purpose made in sections so that only a part of the channel need be uncovered when repair-l -inpg Shall take place .or openings maybe provided in the cover or the upper part of the hearth through which the repairing material can be introduced. l

According to Fig. 2 the inner Wall 5 only of the channel is made with small incliliation while the outer Wall which is in a-less degree exposed to the corrosive action of the 'oath is'essentially vertical..

In both ot' I'these figures it will he noted that the inclination of the sides subject to corrosion have an inclination to the horizonJ4 tal of less than 450. In other words, the in,v clin'ation of the sides must be less than the angle of repose ot' the 't'ettling material in order to be ahle to properly Work the material at the places in the lining to he repaired. lVhat l claim is l. Electric induction furnace. comprising a ring-shaped heartl'i haring a nieltingchannel the inner 'side wall ot which has a less inclination to the horizontal plane anule of repose oi the repairing material `so that such repairing material can be applied and sintered on corroded partsotsaid wall during; operation of the furnace.

2, Electric induction Afurnace` comprising a ring-shaped hearth having a melting channel in which not-h side walls have a less inclination to the horao'ntal plane than the angle of repose of the repairingr material.

Electric induction furnace, comprising a ring-shaped hearth having a melting channel the inner side Wall of which has an inclination lesa than 45 to the horizontal plane. 4, Electric induction furnace; comprising a riiigrshapeil hearth having a in ting channel in which hoth side walls hai an inclination less-z than 450 to the herr/.oi l plane.

in testimony whereof l hart signed my than the u 

